Make an object the new gravity point
Yes, add a force field of type Force. Put it to the center in order to create a spherical world having its own gravitational pull. Use shape &quot;Plane&quot; to have a both sided flat world. As the manual says:

Shape The field is either a Point, with omni-directional influence, or a Plane, constant in the XY-plane, changes only in Z direction.
Strength The strength of the field effect. This can be positive or negative to change the direction that the force operates in. A force field’s strength is scaled with the force object’s scale, allowing you to scale up and down scene, keeping the same effects.